Defect inspection of a composite component is performed with use of an ultrasonic flaw detector by a transmission method or a reflection method. The inspection by the transmission method is performed in the following manner: receive an ultrasonic wave that has been transmitted through a composite member; and determine based on the energy of the received ultrasonic wave whether or not the composite member has a defect. On the other hand, the inspection by the reflection method is performed in the following manner: receive an ultrasonic wave that has reflected on a composite member; and determine based on the energy of the received ultrasonic wave whether or not the composite member has a defect.
There is a known inspection apparatus that performs inspection in a manner to switch between the transmission method and the reflection method (see Patent Literature 1, for example). In the inspection apparatus disclosed in Patent Literature 1, a pair of probes is disposed such that the probes are positioned at both sides of a composite member in a manner to face each other. The inspection apparatus includes switching means that switches between transmission-type inspection in which both of the pair of probes are utilized and reflection-type inspection in which only one of the probes is utilized. The inspection apparatus disclosed in Patent Literature 1 includes a feeder that feeds composite members having the same shape (inspection objects; brake pads) to an inspection unit.
At the time of performing defect inspection of a composite component, it is necessary to perform calibration using a calibration test piece (a standard sample) before and after the defect inspection in order to verify the soundness of the ultrasonic flaw detector. In order to perform such calibration of the ultrasonic flaw detector, there is a known ultrasonic flaw detector that makes it possible to perform calibration and verification of probes on an off line under the same conditions as those of an actual line (see Patent Literature 2, for example). The ultrasonic flaw detector disclosed in Patent Literature 2 includes: a plurality of calibration test pieces that are arranged in the direction of a conveyer line and on each of which an artificial flaw is formed; and a truck that is fitted with a plurality of probe heads and movable in the width direction of a steel plate and that moves the probe heads over the calibration test pieces.